LEDs in horticultural lighting

Carolin Horst, applications engineer and expert for solid state lighting at Osram Opto Semiconductors, explores the impact LEDs are having on the horticulture market

Unlike general lighting, lighting in horticulture, end users are dealing with yield and a measurable, objective quantity. Growers are exposed to much more potential risk than someone who explicitly deals with general lighting. The use of data and proven results plays a strong role in selling horticultural lighting, as growers need to have the assurance that the product is tried and tested.

The application situation is also quite challenging for lighting – they need to be able to withstand environmental influences such a high temperatures and humidity or sprinkler systems used in commercial greenhouses.

In recent years, LED lighting for horticulture applications, in particular plant-growth research and production in the controlled environment, has dramatically increased. The benefits of using LED technology for energy savings and performance improvement have been quickly recognised by researchers, plant growers, and greenhouse or controlled-environmental-chamber manufacturers, as well as government and energy saving experts. Therefore, LED horticultural lighting is a fast-growing market.

Since its invention in 1912, HID (high-intensity discharge) lighting, particularly High-Pressure Sodium (HPS) lamps, have led the industry and quickly became the standard in lighting for horticulture. These HPS lamps produce over 100 lm/W, but over a wide wavelength range which is not necessarily optimised to plant growth. The high-power consumption and the heat radiated from HPS luminaires also require a significant distance between the light source and the plants, leaving them primarily suitable for top-lighting systems in green houses. To compensate the heat development, they also often require additional hydration of the plants. Other drawbacks of HPS lamps include a short lifespan of only 8,000 hours.

However, since the turn of the century, the introduction of LEDs has made a significant dent in the market share of HID in horticultural lighting. In the past 10 years alone, COB (chip on board) grow lights on the market have made huge advances in their ability to grow plants.

Today LED lighting can provide optimised light for plant growth by saving up to 40 per cent energy cost. Durable and long-lasting LED technology therefore becomes more and more popular and replaces standard horticultural lighting. Due to the optimised light spectrum at 450, 660 and in certain applications 730 nanometers, LED based luminaires can provide the perfect lighting for all types of plants and flowers, allowing the grower to adapt the light exactly to the needs of various crops.

Indoor growers are also now being offered more options for horticultural lighting than ever. In fact, horticultural lighting is the LED industry’s most explosive new market – according to market analysts the market for packaged LEDs in horticulture is growing at a compound annual growth rate (CAGR) of 28 per cent between 2016 and 2022, rising to more than 357 million USD by 2022.

The speed at which horticultural lighting has developed has ushered in more functional and affordable lighting, most notably within the LED range. For any prospective growers, the benefits of LEDs have been hard to ignore when browsing for horticultural lights. Cost efficiency is achieved through lower energy consumption, a long lifetime and low maintenance needs, also, additional watering is not required.

Within all aspects of technology, the need for control is becoming more prevalent. Having a tighter grip on a technology allows for increased customisation and the reduction of risk. The rise of indoor crop production and creation of huge indoor farming facilities has blossomed due to the increased demand for further control over crops. This trend has occurred for reasons such as pest control, and shielding plans from environmental damage to increase yields.

Heat has been a remarkably important factor in deciding buying trends for horticulturists. Heat needs to be adjusted depending on a number of reasons, the location of the plants, the time of year, and what plants are being grown. Some plants react negatively to heat, and these factors are something growers need to take into account when buying lights.

LEDs hold an advantageous position over regular lightbulbs due to the fact that they can easily be controlled to emit specific strengths and wavelengths of light. Having such control over a plant can influence it in a number of ways, controlling the shape and even the taste of the plant. Botanical diseases are also more easily identifiable and controllable under an LED. Multi-layer cultivation with LED-based lighting can reduce the farming footprint and water demand dramatically and ensure a faster time to harvest.

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